Consequences of MDEA injection in Crude oil export line?

[coolamjadkhan]

Hi,

We were involved in commissioning of a sour gas platform with 9000 ppm H2S conc, In export crude we were getting very high conc. of H2S gas, Recently client had started adding MDEA in export line to absorb excess H2S present in export crude, after few months all three crude oil export pumps are badly damaged. we strongly believe that MDEA injection has caused this problem. If someone can share any ideas what kind of reactions takes place between crude oil & MDEA? It will be very helpful.

Also if someone has any kind of such experience please share.

Thank you!

[Javarga5691]

Hello, I am afraid i am unable to help in the chemical reaction side of the system you described (what i know you can also find on internet concerning the characteristics and the nature of aqueaous MDEA solutions used in gas treatment applications). But I would be highly interested in knowing what damages you observed on those pumps. The nature of damages may allow narrowing down the possible root causes; whether they were due to solid erosion, corrosion, or other. I would also love to hear about the efficiency of this MDEA injection method in reducing H2S content of the export crude.
I may further note that injection of MDEA into liquids for absorbing acidic components is not very common, at least in my experience. We face with a similar issue and we use H2S scavenger for this purpose (quite expensive though). We also plan to replace this method with sweet or inert gas stripping in near future.

[BigBubba]

Most Amine based acid gas recovery units are made of stainless steel. The drains are segregated because the compound is so corrosive. So in a carbon steel based system it is highly likely that the MDEA is causing corrosion. However without all of the facts it is difficult to give a definitive answer that the MDEA is causing the pump failures but it is highly likely.